174 FREDERICK TILNEY AND LUTHER F. WARREN 



cm. 



Longitudinal 0.8 



Transverse 0.6 



Anteroposterior 0.5 



Nerve fibers are found in the base of the epiphysis. Histo- 

 logically, the pineal body consists principally of a delicate con- 

 nective-tissue framework, in the meshes of which are found 

 lymphatic elements. Many pigment cells are also found having 

 a brownish color and occupying usually a perivascular position. 

 Neuroglia and ependymal cells are also present. 



2. Equus asinus. Cutore ('10). 76 In this species the pineal 

 body is larger than in the horse and its form is oval. Its diam- 

 eters are: 



cm. 



Longitudinal 1.5 



Transverse 0.6 



Anteroposterior 0.6 



Its histology is much the same as that of the horse. Peri- 

 vascular pigmented cells are present in large numbers. 



3. Equus mulus. Cutore ('10). 76 The pineal body in this 

 species is relatively large. Its diameters are: 



cm. 



Longitudinal 1.5 



Transverse 0.6 



Anteroposterior 0.6 



It is conical in form. Histologically, it consists of paren- 

 chymal cells containing pigment granules. In addition, there 

 are ependymal cells, neuroglia, and lymphatic elements. 



4. Elephas indicus. Parisini. 300 In this animal Parisini 

 reports the presence of concretions. 



INSECTIVORA. 1. Erinaceus europaeus. Cutore ('10). 76 In 

 this species the epiphysis is triangular and is situated in the 

 intercollicular sulcus. It presents a well developed pineal recess. 

 Histologically, its elements resemble those of other mammals, 

 the cells being arranged in acini, not unlike the cellular forma- 

 tions in the hypophysis. 



RODENTIA. 1. Talpa. Ganser ('82). 142 In this form the 

 pineal body was considered an unpaired ganglion habenulae. 

 It receives fibers from the thalami and the posterior commissure. 



